Motor starter relay



Nov. 12, 1963 c. s. HlcKLE Erm.

MOTOR STARTER RELAY 2 Sheets-Sheet 1 Filed June 15, 1960 NOV- 12, 1963 c. s. HlcKLE E-rAL MOTOR STARTER RELAY 2 Sheets-Sheet 2 INV ENTORS Cz. x05 5. b//c/af XTTORNEY A Filed June 15, 1960 United States Patent O Filed `lune 15, 1960, Ser. No. 36,343 3 Claims. (Cl. 200-87) r[he present invention relates to an improved magnetically operated motor starter relay for electric motors.

It is common practice in the electric motor control Vart to provide a relay for energizing the starting windings of certain types of electrical motors during star-ting of the motor and to de-energize the winding after the motor has atta-ined running speed. One relay of this type comprises a solenoid connected across the starting winding and which attracts a switch operating armature to open a normally closed switch vin the starting winding circuit in response to a predetermined rvoltage across the starting winding. The present invention is directed to an proved relay ot the Itype mentioned in which the armature is pivoted and is biased from the solenoid core by a sirnple spring arrangement, preferably a flat spring which is connected to the armature so that the tongue applied to the armature by the spring is reduced `when the armature is attracted to the `switch opening position by the solenoid whereby the 'armature is held in that position throughout normal operating Voltage drops in the motor circuit, which may be somewhat less than the initial energ-ization voltage required to cause opening of the switch or drawing of the armature to the solenoid core.

A further object of the invention is the provision `of a simplified armature arrangement in a relay of the type mentioned for actuating a switch to be connected in the starting winding circuit of a motor and fwhich provides tfor a positive opening movement of the switch.

Other objects and advantages of the invention will be apparent from lthe following description of la preferred form of the invention, reference being made to the accompanying drawings, wherein:

FIG. 1 is a-side elevational view of Ia motor starter -relay embodying the invention, the relay being shown in its cle-energized position.

FIG. 2 is a View similar to FIG. 1 but showing the relay in its energized position;

FIG. 3 is a sectional view taken substantially along line 3-31of FIG. l;

FIG. 4 is a sectional view `taken substantially along l-ine 4-4 of FIG. 2;

FIG. 5 is a sectional view taken substantially along line 5--5 of FIG. 4 but on a larger scale, showing the parts of the relay in the de-energized position; and

FIG. 6 is ra View similar -to FIG. 5 but sho-wing the parts of the relay in the energized position.

In the form of the invention shown, a motor starter relay is provided which comprises a panel 10 formed of suitable insulating material, such as laminated phenolic plastic, and which has a cover 11 of insulating material attached thereto by a screw, not shown. In FIGS. l, 2, 5 and 6, the relay is shown with the cover removed. A switch mechanism is attached to panel rand comprises a terminal bracket 12 riveted at :one end to the panel and formed with a forwardly projecting strip portion 13 having an odset at the outer end to which a fixed contact 14 is riveted. The anchored end of strip 13 is bored and tapped to receive a terminal screw 15 inserted through an opening in panel 10 by which a lead from the motor Starter winding may be connected to the switch. A second bracket 18 is attached to panel 10 by a rivet 19 and it includes a forwardly extending strip portion 20 to which one end of a spring contact arm 21 is attached and the opposite end of which arm has a contact 22 3,1 101,785 Patented Nov. 12, 1963 ICC thereon arranged to engage contact 14. Contact -arrn 21 is preferably formed of beryllium copper, or other suitable spring material, and is normally -biased to engage contact 22 with contact 14. A screw 23 is threaded into rivet 19 for attaching the other lead of the motor starting circuit to the switch mechanism, so that when contacts L14 and 22 are engaged and the motor circuit is energized, the circuit for the starting winding is established through these closed contacts.

` Contact arm 2x1 is arranged to be ilexed and separate contact 22 from contact 14 by an armature 24 of a solenoid mechanism, the armature being pivoted to an upright support 25 formed on bracket 18. Armature 24 comprises an L shape strip of iron which is reduced in Width to provide two opposite shoulders 26. Upright 25 has a central opening 27 through which the reduced portion of armature 24 projects, and the upper portion of the upright is bent rearwardly to provide a shallow V bearing 28 for the edges of shoulders 26, so that armature 24 may pivot on bearings Iformed by shoulder edges 26 engaging in the V bearings 28. The foot portion 29 of |armature 24 has a plastic (Teflon) bumper member 30 riveted thereto, which engages contact arm 21 when the armature is attracted to the position shown in FIGS. 2, 4 and 6, and this member is preferably porous so that it may retain an anti-friction material, such as graphite, to minimize friction with the contact ann.

lArmature 24 is normally urged counter-clockwise to its raised position and into engagement with a stop 31 formed by a tongue on upright 25, `as Viewed in FIGS. 1, 2, 5 and 6, by a llat blow spring 32, one end of which is located in a recess 33, formed in a tongue 34 integral with bracket 18, and the upper end of which is received in a recess 3-5 formed in the under surface of armature 24. The 'distance between the inner walls of the recesses 33 and 35 is less than the length of the spring so that the spring is maintained bowed and is forced to the left hand end of recess 33 land the right hand end of recess 315, as shown. The leverage `of spring 32 tending to urge armature 24 upwardly when the `armature is in its raised position is illustrated by the length of arrow F shown in FIG. 5, Iand when the armature is moved to the position shown in FIGS. 2 and 6, this leverage is reduced by an amount represented by the difference between F and F' resulting from swinging the upper end of spring 32 downwardly about the pivot 28 of the armature. By this arrangement, the force tending 4to rotate armature 24 counter-clockwise is reduced when the armature is in its lowered or switch opening position as shown in FIGS. l2 and 6.

Armature 24 is moved to its switch opening position by energization of a solenoid 40 which may be of conventional construction and which is attached to the bo-ttorn plate portion @41 of bracket `18 so that its cylindrical sides extend parallel to and Ialongside upright 25 and the projection of the cylindrical side adjacent to the upright will pass adjacent to the pivot bearing 28 for armature 24, which extends transversely of the axis off the solenoid and moves to and ffrom the core lat the end of the solenoid as seen in FIGS. 5 and 6. The leads for solenoid 40 are attached to bracket plate 18 and a terminal 42 by which the solenoid is connected across the motor starter winding circuit so as to respond to voltages passing through the starting winding of the motor. Frame 18 serves as a magnetic path for solenoid 40 to 'establish a magnetic flux sufiicient to draw armature 24 downwardly to its core and open contacts 14 and 22 upon the attainment of a predetermined voltage across the solenoid and thereby open the starting winding circuit. The shift in the upper end of spring 32 imposes less torque on ,armature 24 tending .to maintain -it in the switch open position although the voltage in the solenoid during running of the motor may be `below that required to initially draw the armature to the switch opening position and therefore, such transient reduction in voltage does not cause reclosing of the motor starter circuit switch.

It will be seen that the pivotal arrangement for armature 24 is simple and the number of parts comprising the relay is at a minimum.

The action of member 30 on contact arm 22 provides a positiv-e force to move the contact anm to the left and at thesame time impart-s a rocking or prying action to contact 22 so as to break |any welds ywhich may tend to :form between the contact members.

It is to Ibe understood that While We have described but `oneform of rthe invention, other fonms, modifications and adaptations could be made, all failing Awithin the scope or the claims which follow.

Weclaim:

1. A motor starting relay comprising a frame, -a switch mechanism carried on said drame, a cylindrical solenoid including a core, an armature adapted to be attracted to one end of said solenoid and arranged to actuate said switch mechanism, means to support said armature to rotate about a pivot adjacent to one side of the projection of the cylindrical side of said solenoid, and a bow spring having one end vfixed and the opposite end engaging said armature adjacent to'said pivot and between said pivot and projectionvof the adjacent cylindrical edge of said solenoid for urging said Iarmature in a direction 'about its pivot away from said .solenoid core, said spring being positioned so that the center line thereof is shifted relative to said pivotrwhen said armature moves to the core of said solenoid thereby .causing the effective Leverage of said spring on said armature about said pivot to be reduced.

2. A motor stanting relay comprising an L shape frameincluding an upright portion and a laterally projecting foot portion at one end of said upright portion, a :solenoid including a core Iand `attached to said foot portion and :extending alongside said upright pontion, an yarmature pivoted :to said upright portion lat the other end thereof, said armature being pivoted adjacent to the projection of the Aadjacent side yof said solenoid yand projecting across the core of said solenoid, a tongue projecting laterally from said one end of said upright portion and on the opposite side thereof relative to said -foot portion, a flat spring having one end supported ion said tongue' and extending longitudinally of said armature and having the opposite end engaging said armature adjacent to the pivot ttor said armature land between said pivot and the projection of the adjacent edge of said armature for unging said armature from said solenoid so that the center line thereof is shifted relative to said pivot when said armature moves to the core of said solenoid thereby cans# ing the eiective leverage of said spring on said armature about said pivot to be reduced, and a switch operated by movement of said armatore.

3. A motor starting relay comprising ran L shape frame including an upright portion yand a later-ally projecting foot portion at one end of-said upright portion,

a solenoid including a core and Iattached to said foot portion and extending alongside said upright portion, an armature pivoted to said upright portion at the other end thereof Iand adjacent Vto :the projection of the adjacent side of said solenoid, said armature projecting across the core of said solenoid, a tongue projecting laterally from said one end of said upright portion and on the opposite side thereof relative to said toot portion, a flat spring having one end supported Aon said tongue and the opposite end engaging said armature adjacent to the pivot for said armature and between said pivot for said armature and the projection of the adjacent side lof said armature for urging said armature from said solenoid so that the center line thereof is shifted relative to said pivot when said armature moves to the cone of said solenoid thereby causing the effective leverage of said spring on said armature labout said pivot to be reduced, and a switch operated by movement of said armature, said switchcomprising a resilient ilat contact arm, means supporting one end of said contact anm in a position to ensure said arm to extend parallel to said iiat spring, a contact carried at the other end of said arm, and a fixed contact arranged to be engaged by the rst mentioned contact, said armature having a part arranged to wedge against and move said contact arm when said armature is moved to one position.

References Cited in the file of this patent UNITED STATES PATENTS 2,585,684 Roggenstein Feb. 12, 1952- 2,896,132 Sauer July 21, 1959 2,904,653 Leo Sept. 15, 1959 2,913,548 Martin Nov. 17, 1959 .2,916,580 Seele Dec. 8, 1959 2,929,001 Wal-lace etal Mar. 15, 1960 

1. A MOTOR STARTING RELAY COMPRISING A FRAME, A SWITCH MECHANISM CARRIED ON SAID FRAME, A CYLINDRICAL SOLENOID INCLUDING A CORE, AN ARMATURE ADAPTED TO BE ATTRACTED TO ONE END OF SAID SOLENOID AND ARRANGED TO ACTUATE SAID SWITCH MECHANISM, MEANS TO SUPPORT SAID ARMATURE TO ROTATE ABOUT A PIVOT ADJACENT TO ONE SIDE OF THE PROJECTION OF THE CYLINDRICAL SIDE OF SAID SOLENOID, AND A BOW SPRING HAVING ONE END FIXED AND THE OPPOSITE END ENGAGING SAID ARMATURE ADJACENT TO SAID PIVOT AND BETWEEN SAID PIVOT AND PROJECTION OF THE ADJACENT CYLINDRICAL EDGE OF SAID SOLENOID FOR URGING SAID ARMATURE IN A DIRECTION ABOUT ITS PIVOT AWAY FROM SAID SOLENOID CORE, SAID SPRING BEING POSITIONED SO THAT THE CENTER LINE THEREOF IS SHIFTED RELATIVE TO SAID PIVOT WHEN SAID ARMATURE MOVES TO THE CORE OF SAID SOLENOID THEREBY CAUSING THE EFFECTIVE LEVERAGE OF SAID SPRING ON SAID ARMATURE ABOUT SAID PIVOT TO BE REDUCED. 